Crassula decumbens Thunb.
Cape crassula
Small glabrous, annual herb, dense and much-branched but not forming mats; stems 2-7-(10) cm long, decumbent to erect, rooting at lowest nodes, especially in moist conditions. Lvs connate at base, decussate, 3-6 × 0.4-1.5 mm, 0.4-0.9 mm thick, linear-lanceolate, flattened, convex above and beneath, green or greenish brown, without hydathodes; apex subacute or acute. Infl. of 1-several, elongated, much-branched cymes; bracts leaflike. Fls 4-merous, several to many, not star-like, 3-4 mm diam.; pedicels c. 1-2 mm long at anthesis, at least some 5-10-(15) mm long at fruiting. Calyx 1.5-3.5 mm long; lobes lanceolate to triangular-lanceolate. Petals united at base, c. 1.3-2 × 0.7-1 mm, broadly ovate, white, often tinged pink, obtuse, usually slightly < or ± = calyx, occasionally slightly > calyx. Stamens 0.8-1.1 mm long, > carpels at anthesis. Scales 0.15-0.2 mm long, widely T-shaped or very broadly wing-like, dark red. Follicles with 4-10 seeds, smooth. Seed 0.3-0.4 × c. 0.15 mm, oblong, strongly papillate. Fruiting infl. lacking plantlets.
N.: N. Auckland, Auckland, Coromandel, S. Auckland, Taranaki, Manawatu, Wellington area; S.: Cape Foulwind (near Westport), Hokitika, Kaikoura.
Southern Africa, temperate Australia 1883
In and around settled areas in open, rather dry habitats; waste ground, shingle and gravel surfaces, pavement crevices, poor pasture, paths, roadsides, riverbeds, railway yards, coastal cliff talus, behind beaches.
FL Sep-Feb.
C. decumbens is sometimes mistaken for an indigenous sp. because it belongs to sect. Glomeratae which is otherwise represented in N.Z. only by indigenous spp. However, it usually grows in very artificial habitats. Also, the diffuse, much-branched cymes with pedicels commonly between 5 and 10 mm long at fruiting, giving the plant a bushy appearance, and the dark red ± widely T-shaped scales of the fls distinguish it from all the indigenous Crassula spp. N.Z. plants belong to var. decumbens. Australian plants of var. decumbens are said to be 5-merous, whereas all N.Z. plants examined were 4-merous. However, Tölken (1985, op. cit.) recorded 4- and 5-merous fls from South Africa. The sp. was first recorded in N.Z. as Tillaea trichotoma.
